The medullary cavity (medulla, innermost part) is the central cavity of bone shafts where red bone marrow and/or yellow bone marrow (adipose tissue) is stored; hence, the medullary cavity is also known as the marrow cavity. Located in the main shaft (cortical bone) of a long bone (diaphysis) (consisting mostly of compact bone), the medullary cavity has walls composed of spongy bone (cancellous bone) and is lined with a thin, vascular membrane (endosteum). However, the medullary cavity is the area inside any bone (long, flat, etc.) that holds the bone marrow. This area is involved in the formation of red blood cells and white blood cells.
Intramedullary is a medical term meaning the inside of a bone. Examples include intramedullary rods used to treat bone fractures in orthopedic surgery and intramedullary tumors occurring in some forms of cancer or benign tumors such as an enchondroma.
An intramedullary reamer is a surgical instrument used in orthopedics to drill a hole into bone to allow a space for a prosthesis or appliance to sit. As shown in FIG. 1, a typical reamer includes three parts: a rasp tip or bit (A1) that is connected to a flexible body (B1) that is connected to a reamer driver via a connector (C1). FIG. 2A shows a typical reamer and manual hand driver. FIG. 2B shows a typical reamer and electromechanical driver. As seen in FIG. 3, the flexible body includes two layers of stainless steel coils that are wound in opposite directions, thereby permitting bending and twisting while reaming. However, when the flexible body bends, biodebris can collect within the corresponding gaps of the stainless steel coils. These gaps are very difficult to clean between uses.
Traditional cleaning methods include handwashing, to include bending the flexible body to expose the gaps for cleaning. The handwashing is followed by ultrasonic cleaning and sanitization. However, the traditional cleaning methods often do not permit easy and thorough access into the gaps. The traditional cleaning methods are suboptimal because when a bending force is applied to one side of the flexible body, the interior of the coils on the one side becomes more expose while the interior of the coils on the other side become more compressed and less exposed. Therefore, while some biodebris can be accessed, other biodebris becomes further compressed and lodged within the flexible body. Repeated bending and cleaning, while handwashing and/or while ultrasonic cleaning, can be burdensome and may not result in 100% exposure and cleaning. In short, the traditional cleaning methods do not permit easy and thorough removal of all bioburden. That is, even when the reamer appears clean, it is likely to have blood and bone marrow lodged into small areas between the spirals and within the cracks. If bioburden is still on the reamer, it cannot be properly sanitized. In addition, hidden bioburden poses a threat to patient health during surgery. It is necessary, therefore, to design a device that can effectively clean bioburden from the cracks and the hollow inner portion of the reamer.
Thus, as discovered by the present inventors, what is needed is an improved method and device for cleaning biodebris from the interior of the coils of the flexible body of an intramedullary reamer.